IV27971: On Linux platforms, FDC records appear with probe ZF225050. Performance of user/group lookup can then be slower.

Subscribe

You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • On Linux platforms, when using the environment variable
    MQS_GETGROUPLIST_API=1 to cause the queue manager to use
    getgrouplist() and the user is a member of group(s) that
    contain a very large number of other users, this FDC can be
    seen.
    
    The user/group lookup operation falls back to an alternative
    method, which then succeeds, so the impact to users is minimal.
    But, because the alternative method is less optimal when using
    large groups, the result is that performance of some activities
    can be a little slower.
    
    The FDC record contains:
    
    Probe Id          :- ZF225050
    Component         :- zfuGetGroupsUsingGetgrouplist
    Major Errorcode   :- krcE_UNEXPECTED_ERROR
    
    A trace shows:
    
    --{  xcsGetgrgid
    rcunix(34) errno(34)
    --}! xcsGetgrgid rc=Unknown(FFFFFFFF)
    

Local fix

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    Users on Linux platforms, when using the environment variable
    MQS_GETGROUPLIST_API=1 is in use, and the user is a member of
    group(s) that contain a very large number of other users.
    
    Platforms affected:
    Linux (Power),Linux (s390x),Linux (x86),Linux (x86-64),
    Linux (zSeries)
    
    ****************************************************************
    PROBLEM SUMMARY:
    The queue manager was querying the operating system for the
    groups in which a user belongs. The operating system was
    returning a group structure containing more users than would fit
    in the buffer being supplied. Instead of reallocating the
    buffer and retrying the operation, the WebSphere MQ code instead
    wrote the FDC and gave up, to try the less-optimal method
    instead.
    

Problem conclusion

  • The WebSphere MQ code has been changed to retry the operation
    in the case where the buffer was too small. This is not an
    error case, so the FDC record is no longer written.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
                       v7.0
    Platform           Fix Pack 7.0.1.10
    --------           --------------------
    Linux (x86)        U853084
    Linux (x86-64)     U853088
    Linux (zSeries)    U853085
    Linux (Power)      U853086
    
                       v7.1
    Platform           Fix Pack 7.1.0.3
    --------           --------------------
    Linux (x86)        7.1.0.3
    Linux (x86-64)     7.1.0.3
    Linux (zSeries)    7.1.0.3
    Linux (Power)      7.1.0.3
    
    Platform           v7.5
    --------           --------------------
    Multiplatforms     7.5.0.1
    
    The latest available maintenance can be obtained from
    'WebSphere MQ Recommended Fixes'
    http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006037
    
    If the maintenance level is not yet available information on
    its planned availability can be found in 'WebSphere MQ
    Planned Maintenance Release Dates'
    http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006309
    ---------------------------------------------------------------
    

Temporary fix

Comments

APAR Information

  • APAR number

    IV27971

  • Reported component name

    WMQ LIN X86 V7

  • Reported component ID

    5724H7224

  • Reported release

    701

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2012-09-14

  • Closed date

    2012-10-25

  • Last modified date

    2012-10-25

  • APAR is sysrouted FROM one or more of the following:

  • APAR is sysrouted TO one or more of the following:

Fix information

  • Fixed component name

    WMQ LIN X86 V7

  • Fixed component ID

    5724H7224

Applicable component levels

  • R701 PSY

       UP



Rate this page:

(0 users)Average rating

Document information


More support for:

WebSphere MQ
APAR / Maintenance

Software version:

7.0.1

Reference #:

IV27971

Modified date:

2012-10-25

Translate my page

Machine Translation

Content navigation